As top plate conveyor devices, a top plate conveyor device has been known in which adjacent top plates are rotatably connected to each other by connecting pins or the like to form a chain shaped-element as a configuration for endlessly connecting a plurality of top plates to each other.
One such device is shown in FIG. 6. A top plate conveyor device 600, has a number of top plates 610 rotatably connected to each other by connecting pins 615 to form an endless chain shape and are formed such that the top plate conveyor device is stretched between sprockets 630 to load articles thereon and convey them. Guide rails 640 are provided along the top run, i.e. the conveying portion, of the conveyor to underlie the back surfaces of the chain-shaped top plates 610 to support the article loading surface.
There were such problems in the top plate conveyor device 600 caused by vibrations and noises generated by the rolling of the connecting pins 615, and the contacts between top plates 610 and between the top plate 610 and the sprocket 630, and elongation is generated in the entire chain and breakage is generated, by wear of the connecting pins 615 and the like.
Further, another conveyor device has been known as a high strength conveyor device in which vibrations and noises are low and elongation is not liable to occur. In this device the top surface of an endless belt is made of rubber, such as urethane or the like, and this surface is used as a loading surface and a back surface of the belt is supported by guide rails.
As shown in FIG. 7, the conveyor device 700 is formed such that a toothed belt 720 made of rubber such as urethane or the like is stretched between sprockets 730. Articles P are loaded on the toothed belt 720 to be conveyed. A back surface of the toothed belt 720 has tooth portions 721 where crest portions 722 and valley portions 723 are alternately provided at the equal intervals. Back surfaces for conveying portions in the toothed belt 720 are provided with guide rails 740 for supporting loading surfaces.
Such a conveyor device 700, where rubber such as urethane or the like used in the toothed belt 720 which has a higher frictional coefficient as compared with resin used in the top plates of a usual top plate conveyor device, there were problems that the conveyor device needs large driving force for driving a conveyor due to frictional resistance with a guide rail 740 on a back surface and sliding of accumulated articles on the loading surface is difficult.
To overcome these problems another article transferring top plate conveyor device has been known in which a plurality of top plates are connected to an endless belt.
As shown in FIGS. 8 and 9, the top plate conveyor device 800 is formed such that a plurality of top plates 810 are attached to a surface of an endless belt 820 having longitudinally-space protrusions 826. One end of the top plate 810 in the transfer direction is pivotally connected to another top plate 810 by hinges 817 (see FIG. 9), and the other end of the top plate 810 in the transfer direction is provided with a fitting portion 815, which can be fitted to attached the protrusions 826 in an concave portion/convex portion engagement. Further, on the endless belt 820 has a locking pin receiver 825 between the protrusions 826. The underside of the hinge 817 is provided a locking pin 816, which can be securely fitted into the receiver 825. See Japanese patent publication No. 2002-503193 (on pages 12 to 14, FIGS. 1 to 4).